Subban is one of the best two-way defensemen in the league thanks to his above-average skating ability and playmaking capabilities. He won the James Norris Memorial Trophy as the league's best defenseman in 2013 and was in the top 15 in voting two other years.
However, his fiery personality has gotten him into trouble at times:
It also affects his relationships with his teammates, as TVA Sports' Louis Jean pointed out that he and captain Max Pacioretty "are not best friends. [Subban] is a guy who does rub others the wrong way," (via Luke Fox of Sportsnet).
Toward the end of the 2015-16 season, rumors swirled that Subban and head coach Michel Therrien were feuding after Therrien blamed his defenseman for losing a game in February. The two denied having any problem, however, per TSN.ca.
After the Canadiens had their worst full campaign since 2011-12 last season, which had a lot to do with the absence of goaltender Carey Price, Montreal could have possibly viewed Subban as a player who pollutes the team's chemistry and therefore was an expendable piece in order to bring in a big-time talent such as Weber.
Stats courtesy of Hockey-Reference.com.